import java.util.LinkedList;
import java.util.Queue;

public class demo1 {
    boolean[][] flag;
    int m;
    int n;
    int sum=0;
    public int getMaximumGold(int[][] grid) {
        m=grid.length;
        n=grid[0].length;
        flag=new boolean[m][n];
        for(int i=0;i<m;i++){
            for(int j=0;j<n;j++){
                if(grid[i][j]!=0){
                    flag[i][j]=true;
                    dfs(grid,i,j,grid[i][j]);
                    flag[i][j]=false;
                }
            }
        }
        return sum;
    }
    int []dx={0,0,1,-1};
    int []dy={1,-1,0,0};
    public void dfs(int[][] grid,int i,int j,int s){
        sum=Math.max(sum,s);
        for(int k=0;k<4;k++){
            int x=i+dx[k];
            int y=j+dy[k];
            if(x>=0&&x<m&&y>=0&&y<n&&!flag[x][y]&&grid[x][y]!=0){
                flag[x][y]=true;
                dfs(grid,x,y,s+grid[x][y]);
                flag[x][y]=false;
            }
        }
    }
}
